The effect of nitrogen fertilisation on the growth, yield and quality of swiss chard (Beta vulgaris var. cicla)
| dc.contributor.advisor | Engelbrecht, G. M. | |
| dc.contributor.advisor | Ceronio, G. M. | |
| dc.contributor.author | Motseki, Pontso Christina | |
| dc.date.accessioned | 2018-04-04T07:30:20Z | |
| dc.date.available | 2018-04-04T07:30:20Z | |
| dc.date.issued | 2008-05 | |
| dc.description.abstract | English: The sustainability of subsistence farming associated with the health of rural communities’ necessitated research on Swiss chard as it forms an integral part of food consumed by the poor in developing countries. Two separate pot experiments were carried out during the 2005/06 and 2006/07 seasons in the glasshouse of the Department of Soil, Crop and Climate Sciences at the University of the Free State. The objective of this study was to determine the effect of nitrogen fertiliser on growth, yield and quality of Swiss chard. The first pot trial was conducted to evaluate the effect of five nitrogen levels (0, 50, 100, 200, 400 kg N ha-1) and four application times on the growth, yield and quality of two Swiss chard cultivars (‘Fordhook Giant’ and ‘Rhubarb’). Two Swiss chard seedlings were planted per pot, filled with topsoil of the fine sandy loam Bainsvlei form. Two weeks after planting plants were thinned to one seedling per pot. Different nitrogen levels were applied to the relevant pots as follows: once every second, fourth, sixth or eighth week. It was only the total dry mass per plant and total nitrogen content per leaf of ‘Rhubarb’ plants that was significant higher than that of ‘Fordhook Giant’. The other parameters measured for the two cultivars did not differ significantly from each other. Nitrogen levels positively influenced the early growth, yield and quality parameters measured. It was the highest nitrogen level (400 kg N ha-1) that resulted in the highest number of leaves harvested, leaf fresh and dry mass, leaf area and leaf nitrogen content. Nitrogen application times significantly influenced only the early growth of Swiss chard plants and the nitrogen content of leaves. Early plant growth reacted better where nitrogen was split into three equal applications (T4). The total nitrogen content of Swiss chard leaves was significantly higher where nitrogen was split into five equal (T2) or three equal (T4) applications. In the second pot trial the effect of different nitrogen sources applied at different levels on the growth, yield and quality of Swiss chard cultivars was determined. The response of Swiss chard plants to nine nitrogen levels (0, 100, 200, 300, 400, 500, 600, 700, 800 kg N ha-1) from six different nitrogen sources (ammonium nitrate, potassium nitrate, calcium nitrate, ammonium sulphate, urea ammonium nitrate and urea) were studied. Based on the findings of this study, nitrogen significantly influenced growth, number of leaves harvested, leaf fresh and dry mass, leaf area and leaf nitrate content of ‘Fordhook Giant’ plants with best results obtained at 800 kg N ha-1. Nitrogen sources did not influence either the total number of leaves harvested nor the fresh mass of harvested Swiss chard leaves. In both cases, ammonium nitrate gave the best results and calcium nitrate the poorest. Urea influenced the leaf area positively followed by urea ammonium nitrate, with calcium nitrate resulting in the smallest leaf area per plant. Dry mass of Swiss chard leaves was also significantly higher where urea was used as nitrogen source compared to where calcium nitrate was used. No significant differences amongst the other nitrogen sources. Ammonium nitrate and potassium nitrate significantly stimulated the accumulation of nitrate in Swiss chard leaves, whereas the other nitrogen sources did not play any role in nitrate accumulation in the leaves of Swiss chard. | en_ZA |
| dc.description.abstract | Afrikaans: Die volhoubaarheid van bestaansboerdery, tesame met die gesondheid van landelike gemeenskappe, noodsaak navorsing op snybeet juis omdat dit so ‘n integrale deel van arm gemeenskappe se voedselbehoefte uitmaak. Twee afsonderlike potproewe is gedurende die 2005/06 en 2006/07 seisoen in die glashuise van die Departement Grond-, Gewas- en Klimaatwetenskappe by die Universiteit van die Vrystaat uitgevoer. Die doel van die studie was om die invloed van stikstofbemesting op die groei, opbrengs en kwaliteit van snybeet te ondersoek. Die eerste potproef is uitgevoer om die invloed van vyf stikstofpeile (0, 50, 100, 200, 400 kg N ha-1) en vier toedieningstye op die groei, opbrengs en kwaliteit van twee snybeet cultivars (‘Fordhook Giant’ en ‘Rhubarb’) te ondersoek. Twee saailinge is aanvanklik per pot, gevul met grond (fyn sandleem Bainsvleivorm), geplant. Na twee weke is die saailinge uitgedun tot een per pot. Verskillende stikstofpeile is as volg aan die relevante potte toegedien: een keer elke tweede, vierde, sesde of agste week. Dit is slegs die totale droë massa per plant en die totale stikstofinhoud per blaar van ‘Rhubarb’ wat betekenisvol verskil het van ‘Fordhook Giant’. Die ander parameters het nie betekenisvol verskil tussen die twee cultivars nie. Die vroeë groei (eerste agt weke na plant), opbrengs en kwaliteit van snybeet is positief deur die verskillende stikstofpeile beïnvloed. Die hoogste stikstofvlak (400 kg N ha-1) het die beste resultate gelewer vir die aantal blare geoes, vars- en droë massa van die blare, blaaroppervlak en stikstofinhoud van die blare. Die toedieningstye van stikstof het die vroeë groei van snybeet asook die stikstofinhoud van die blare betekenisvol beïnvloed. Vroeë groei van snybeet het beter gereageer waar stikstof toegedien is in minder paaiemente (T4). Die totale stikstofinhoud van snybeetblare was betekenisvol hoër waar stikstof opgedeel is in vyf (T2) of drie (T4) gelyke toedienings. Die tweede potproef is uitgevoer om die invloed van verskillende stikstofbronne, toegedien teen verskillende peile, op die groei, opbrengs en kwaliteit van snybeet te bepaal. Die reaksie van ses stikstofbronne (ammoniumnitraat, kaliumnitraat, kalsiumnitraat, ammoniumsulfaat, ureumammoniumnitraat en ureum) toegedien teen nege verskillende stikstofpeile (0, 100, 200, 300, 400, 500, 600, 700, 800 kg N ha-1) is ondersoek. Resultate van die studie dui duidelik daarop dat stikstof ‘n positiewe invloed op groei, aantal blare geoes, blaarvars en –droë massa, blaaroppervlak, asook die nitraatinhoud van die blare gehad het. Die beste resultate is verkry waar 800 kg N ha-1 toegedien is. Stikstofbronne het nie die totale aantal blare geoes of die varsmassa van die blare van snybeet betekenisvol beïnvloed nie. In beide gevalle het ammoniumnitraat die beste resultate gegee en kalsiumnitraat die swakste. Ureum het die blaaroppervlak van snybeet positief beïnvloed gevolg deur ureumammoniumnitraat terwyl kalsiumnitraat die swakste gevaar het. Droë massa van snybeet se blare was betekenisvol hoër waar ureum toegedien is as waar kalsiumnitraat toegedien is as stikstofbron. Ammoniumnitraat en kaliumnitraat het die akkumulasie van nitraat in die blare van snybeet betekenisvol gestimuleer terwyl die ander stikstofbronne nie ‘n betekenisvolle rol gespeel het nie. | af |
| dc.identifier.uri | http://hdl.handle.net/11660/8091 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Nitrogen application level | en_ZA |
| dc.subject | Nitrogen application time | en_ZA |
| dc.subject | Leaf number | en_ZA |
| dc.subject | Leaf area | en_ZA |
| dc.subject | Leaf fresh mass | en_ZA |
| dc.subject | Leaf dry mass | en_ZA |
| dc.subject | Leaf nitrogen content | en_ZA |
| dc.subject | Leaf nitrate content | en_ZA |
| dc.subject | Swiss chard -- Fertilizers | en_ZA |
| dc.subject | Nitrogen fertilizers | en_ZA |
| dc.subject | Swiss chard -- Yields | en_ZA |
| dc.subject | Swiss chard -- Quality | en_ZA |
| dc.subject | Dissertation (M.Sc.Agric. (Soil, Crop and Climate Sciences))--University of the Free State, 2008 | en_ZA |
| dc.title | The effect of nitrogen fertilisation on the growth, yield and quality of swiss chard (Beta vulgaris var. cicla) | en_ZA |
| dc.type | Dissertation | en_ZA |